Android Secure HTTP communication

I'm really new to Android programming, so this may seem silly to do this...but

I want to communicate to a PHP server (I assume using J开发者_运维百科SON is best). So...would I use a HTTP connection or what? IS there anyway to make this 'secure', like if I was sending site user credentials over the wire?

Secure - against what?

Secure against eavesdropping in the middle - just use HTTPS instead of HTTP.

Secure against devices being stolen - introduce user authentication on the site.